Infrastructure as Code

What Is Infrastructure as Code?

Infrastructure as Code (IaC) means describing your entire IT infrastructure – servers, networks, databases, load balancers, firewalls – in code instead of configuring it manually through web consoles or command lines. This code is versioned, tested, and automatically deployed – just like application code.

For mid-market companies, IaC solves a fundamental problem: infrastructure that only exists in the heads of individual administrators. When the sole admin who configured the production server leaves the company, critical knowledge is lost. With IaC, every configuration is documented, traceable, and reproducible.

Benefits of Infrastructure as Code

• Reproducibility: Identical environments at the push of a button. Staging and production are guaranteed to be configured the same way.
• Version Control: Every change is tracked in Git. You can always see who changed what and when, and roll back if problems arise.
• Speed: Provision new environments in minutes instead of days.
• Consistency: No configuration drift – infrastructure always matches the defined state.
• Compliance: Security policies can be defined as code and automatically enforced.
• Cost Savings: Fewer manual errors, faster provisioning, and the ability to automatically shut down environments.

IaC Tools Compared

Terraform

Terraform by HashiCorp is the most widely used IaC tool. It uses its own configuration language HCL (HashiCorp Configuration Language) and supports over 3,000 providers – from AWS and Azure to Cloudflare and Datadog. Terraform works declaratively: you describe the desired state, and Terraform calculates the necessary changes.

Pulumi

Pulumi takes a different approach: instead of a proprietary DSL, you can define infrastructure in real programming languages like TypeScript, Python, or Go. This is particularly attractive for development teams that do not want to learn a new language. Pulumi natively supports loops, conditions, and functions.

AWS CloudFormation

CloudFormation is AWS's native IaC service. It is deeply integrated into the AWS ecosystem and often supports new AWS services fastest. Configuration is done in JSON or YAML. Disadvantage: CloudFormation only works with AWS – it is not suitable for multi-cloud scenarios.

Which Tool for the Mittelstand?

For most mid-market companies, we recommend Terraform as a starting point. It is cloud-agnostic, has the largest community, and the best documentation. If your team already works heavily with TypeScript or Python, Pulumi can be an interesting alternative. CloudFormation is only worthwhile if you exclusively use AWS and have no multi-cloud ambitions.

IaC Best Practices for Mid-Market Companies

• Centralise State Management: Store Terraform state in a remote backend (e.g., S3 + DynamoDB) rather than locally, enabling multiple people to work in parallel.
• Use Modules: Create reusable modules for frequently used infrastructure patterns (e.g., a VPC module, an EKS module).
• Separate Environments: Use separate state files and workspaces for dev, staging, and production.
• Code Review for Infrastructure: Treat IaC changes like application code – with pull requests, reviews, and CI/CD pipelines.
• Drift Detection: Regularly verify that actual infrastructure still matches the defined code.
• Secrets Management: Never store credentials in IaC code. Use Vault, AWS Secrets Manager, or similar tools.

IaC as the Foundation for DevOps

Infrastructure as Code is the foundation of every modern DevOps practice. Without IaC, CI/CD pipelines, automated tests, and continuous deployment cannot work reliably. IaC ensures that the infrastructure running your applications is as reliable and reproducible as the applications themselves.